Top End Rebuild on my 1999 Challenger....Advice Needed

[Bow4it]

I have a 1999 Sea-Doo Challenger 1800. Took it out for the week of the 4th and on the last day one engine stopped and would not start again. I chugged in on the other engine and took her out. I got back to the cottage and started the diagnostics. My wife went online found this great forum and she discovered it was water in the gas..........Well she did not know that I already did the basic test first. When I got to the compression test .....cylinder one nearly blew my finger off (limited on tools at the cottage). Cylinder 2...no so lucky. I broke the news to the family and brought her home. Today I finally tore the top end apart. Piston is what to expect when she blows. The cylinder wall is actually in really great shape for blowing a piston. I plan on sending both cylinders out to be honed anyway. It is worth the $50. I am going to get the top end rebuild kit with new matching pistons. I just need to know if there is anything special I need to do when I put this all back together. This is my first Sea-D00 Rebuild. I have done many dirt bikes and some car engines, but is there anything special i should do on this boat engine before I try to start it up. I plan on bleeding the oil line, lining up the rings correctly, no oil in the crank case (correct ?) Has anyone done this already and know of something I need to do that I may miss or not know about???

My cylinder head got pitted up pretty good, so should I get a new one or a used one?? any opinion

Thanks for any help you can offer...........

 

[Dr Honda]

Welcome,

Where in Da' Burgh are you?


Anyway... there's nothing special on a 800 if you are just doing a top-end. If you oversize the pistons... then the RAVE vlaves need clearanced, but it sounds like you are jjust trying to go stock.


Now... with that said... did you measure the bore? The cyl walls can look OK... but if they are a couple thou oversized... then your new top-end won't last long.

My shop is in Latrobe, and if you want a second opinion... just let me know.


Next... before you do a top-end... you need to consider that the lower half is 13 years old... and with the shrapnel from the melted piston... the crank may not be too happy. You may want to consider a full rebuild. (for reliability)


Finally... check the compression on the engine that is still running. Good compression on an 800 engine is 150 psi. If you are under 135... now is the time to do the top end on that engine also. If you avoid the melt-down, the crank is more likely to survive.

 

[Bow4it]

Tony.........
Thanks for the quick reply. I live in South Fayette. I am a graphics teacher at Fox Chapel High and just had to watch your youtube video on the vinyl install. I love cutting the vinyls. You have done some cool work on the boats.

I was going to try to stay stock, but after I send the cylinders out to be honed, I may end up going oversized and the valves will be done as well. Funny you should mention the lower end and the other engine. My buddy just got back from vacation and he has my compression tester and that is my plan for today. I did consider the lower end as well, but I really do not have many hours on this boat and it looks really nice inside. but like you said it is right there ready to be done. I was going to use the WSM Platinum rebuild kit. What is your thought on that??

 

[Bow4it]

One more thing......My top end has some ding marks from the bad piston. Anyway to fix that?? Should I reuse it or buy a new one. Know anywhere to get a used on??

 

[Dr Honda]

Thanks for the complements on the vinyl. I've only had the machine a couple years... and it was just by chance. Basically, I had a buddy, who owed me money, and he gave me the cutter. He worked for a sign company for a bunch of years, and he showed me how to use it, and how to design, cut, and apply graphics.

I originality agreed to take it so I could do some basics... like making hull numbers. But... this summer... selling vinyl has basically covered the costs of my Islandia engine rebuild.

OK... on your engine... the lower half is up to you... but I've seen it a bunch of times. People rebuild the top-end after a failure, and the crank gives out. Normally, the big end of the rod fails, and it comes though the block. SO... on top of the wasted time/money for the top end... they now have a lower half that is no longer feasible to rebuild in the home shop. If you are doing your own work... a rebuild crank will cost you $250, and will bring reliability to your boating experience.

WSM kit's are fine. I've never heard anything bad about them... and I'm using WSM pistons in my own Merc project.

The head is probably fine. Post a pic, and I can tell better. If the damage isn't too bad... just file/sand any sharp edges clean, and re-use it.

You said you are sending the cyl's out to be honed. Where are they going... and what exactly did you tell them to do? Like I was saying before... if they hone them straight... then they may be out of spec when they come back.

 

[Bow4it]

I am sending them out to a dealer where i am buying the pistons. He has been doing SeaDoo engines for over 10 years and has some really good reviews. He is going to hone them to match the new pistons and clean the rave valve ports as well. I dont have the name now,but he is in MI. I did not send them out yet so if you know someone better let me know.........The top end can be cleaned pretty easily so I am not too concerned with that. I think the extra $250 for the crank would not hurt at this point.